diff --git a/C/projecteuler.c b/C/projecteuler.c
index e9076c6..277eead 100644
--- a/C/projecteuler.c
+++ b/C/projecteuler.c
@@ -33,16 +33,10 @@ int is_prime(long int num)
 
 long int gcd(long int a, long int b)
 {
-   long int tmp;
-
-   while(b != 0)
-   {
-      tmp = b;
-      b = a % b;
-      a = tmp;
-   }
-
-   return a;
+   if(b == 0)
+      return a;
+   else
+      return gcd(b, a%b);
 }
 
 long int lcm(long int a, long int b)
diff --git a/Python/projecteuler.py b/Python/projecteuler.py
index f381509..f0ec791 100644
--- a/Python/projecteuler.py
+++ b/Python/projecteuler.py
@@ -19,12 +19,10 @@ def is_prime(num):
     return 1
 
 def gcd(a, b):
-    while b != 0:
-        tmp = b
-        b = a % b
-        a = tmp
+    if b == 0:
+        return a
 
-    return a
+    return gcd(b, a%b)
 
 def lcm(a, b):
     return a * b // gcd(a, b)